Estimation of common cause failure parameters with periodic tests

Anne Barros (1) , Antoine Grall (1) , Dominique Vasseur (2)

1 LM2S - Laboratoire Modélisation et Sûreté des Systèmes
2 EDF R&D MRI - Management des Risques Industriels

In the specific case of safety systems, CCF parameters estimators for standby components depend on the periodic test schemes. Classically, the testing schemes are either staggered (alternation of tests on redundant components) or non-staggered (all components are tested at the same time). In reality, periodic tests schemes performed on safety components are more complex and combine staggered tests, when the plant is in operation, to non-staggered tests during maintenance and refueling outage periods of the installation. Moreover, the CCF parameters estimators described in the US literature are derived in a consistent way with US Technical Specifications constraints that do not apply on the French Nuclear Power Plants for staggered tests on standby components. Given these issues, the evaluation of CCF parameters from the operating feedback data available within EDF implies the development of methodologies that integrate the testing schemes specificities. This paper aims to formally propose a solution for the estimation of CCF parameters given two distinct difficulties respectively related to a mixed testing scheme and to the consistency with EDF’s specific practices inducing systematic non-simultaneity of the observed failures in a staggered testing scheme.

Domaines: Performance et fiabilité [cs.PF]

Anne Barros, Antoine Grall, Dominique Vasseur. Estimation of common cause failure parameters with periodic tests. Nuclear Engineering and Design, 2009, 239 (4), pp.761-768. ⟨10.1016/j.nucengdes.2008.12.013⟩. ⟨hal-02316159⟩